The present invention relates to a seat belt system and more particularly to an improvement in a D-ring for supporting the shoulder belt portion of a safety belt.
A typical seat belt system comprises a retractor upon which seat belt webbing is wound. The seat belt webbing extends from the retractor and is slidable received upon or over a D-ring which is typically attached to the B-pillar of a vehicle by a fastener. The fastener provides a single pivot axis about which the D-ring can rotate. As can be appreciated, as the safety belt slides over a cross or support member of the D-ring, friction forces are generated which requires amongst other things, that the retractor rewind spring be strong enough to overcome this friction. Various attempts have been made to provide a D-ring with the necessary load bearing capacity which is also characterized by a low level of webbing retarding frictional force. U.S. Pat. Nos. 4,389,059 and 4,349,217 are illustrative of D-rings which comprise a roller mechanism for reducing frictional retarding forces. Occasionally, as the D-ring is pulled or rotated about the fastener by the webbing the webbing may slide laterally over and bunch up within a corner of a slot in the D-ring. This slot is typically located just above the cross or support member. This bunching makes it more difficult or impossible to retract the webbing due to increased friction forces until, of course, the webbing is again laid flat on the support member.
It is the object of the present invention to provide a D-ring characterized by a low frictional retarding force and one that is less susceptible to web bunching and one which has a number of degrees of freedom of motion.
Accordingly, the invention comprises: a D-ring or seat belt apparatus for safety belts comprising: a cradle adapted to be mounted to a cooperating structure; a member supported by the cradle and having first means for supporting a shoulder belt portion of a seat belt, the cradle and member including second means for permitting the member to move or rotate side to side relative to the cradle, to move or rotate about a first axis of the cradle and to move or rotate about a second axis generally perpendicular to the first axis. The first means includes a roller and flexible shaft which are rotated by the safety belt. The member is encased in plastic, wherein the plastic provides bearing or bushing surfaces to rotationally support the shaft.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.